1. Field of the Invention
The present invention relates generally to a climate control system for use with an automotive vehicle and more specifically to a climate control system having an air inlet and a door operative to selectively open and close the inlet.
2. Description of Related Art
A motor vehicle climate control system or heating, ventilation and air conditioning (HVAC) system typically utilizes a blower to move and control airflow through the system. Air rush noise occurring in the HVAC system, is a customer comfort concern. A typical HVAC system operates in both a fresh air mode and a recirculation mode. The recirculation mode of the HVAC system draws air from the interior of the vehicle cabin or passenger compartment, while the fresh air mode draws outside air into the vehicle cabin or passenger compartment.
The HVAC system includes a selectively positionable door that opens and closes the respective fresh air inlet and recirculation air inlet and correspondingly enables operation in either the fresh air mode or recirculation mode. The door often includes a full surface or strip of foam glued around and on both sides of the door. The foam functions as a seal to minimize or reduce leakage of airflow past the door when placed in a position where the door closes either the fresh air inlet or the recirculation air inlet. In many cases, the door is pivotally mounted on the housing of the HVAC system and pivots back and forth between the respective fresh air inlet and recirculation air inlet.
The respective fresh air inlet and recirculation air inlet are typically a plurality of slots or apertures located in a flat or planar portion of the HVAC housing. As the door pivots, the radially inward portion, or that portion closest to the hinge, and the radially outward portion, or that portion farthest from the hinge, move different distances with the radially outward portion traveling a greater distance for the same angular movement of the door. The foam layer attached to the door is typically a strip having a uniform thickness. Accordingly, pivoting the door to close one of the respective inlets compresses that portion or section of the foam layer located closest to the door hinge or pivot point more than that portion or section of the foam layer located at the far end of the door or furthest from the hinge. Thus, the stiffness or compressibility of the foam layer limits the travel of the outer end of the door, that is, when the foam layer closest to the pivot point fully compresses the door travel ceases.
In many cases, when the door pivots to close either the fresh air inlet or the recirculation air inlet the stiffness or firmness of the foam layer prevents the outer end of the door from traveling the necessary distance to close the door. Failure to travel the necessary distance correspondingly reduces contact between a portion of the foam layer located at the outer or far end of the door and the housing adjacent or near the fresh air or recirculation air inlet. This allows airflow leakage at the far end of the door, which induces an objectionable door noise such as a whistling sound, door flutter or chatter.
Accordingly, it is desirable to provide a climate control system door assembly that minimizes the possibility and potential of airflow leakage when closing the fresh air or recirculation air inlet to reduce potential airflow noise such as whistling or door flutter.